According to patent Literature 1, etc., a lock device capable of locking the rotation of a vehicle seat, etc., has been known. This lock device includes a base, a hook rotatably provided on the base and a pawl rotatably provided on the base. The hook has a slit into which a striker is able to be introduced. The pawl prevents the rotation of the hook. In this lock device, in order to reduce the size thereof, a spring for urging the hook in the rotation direction is disposed between the base and the hook and a spring for urging the pawl in the rotation direction is disposed between the base and the pawl.